# Activity spaces for HIV risk and prevention among diverse men who have sex with men in Los Angeles

> **NIH NIH R21** · UNIVERSITY OF CALIFORNIA SANTA BARBARA · 2020 · $220,614

## Abstract

Abstract
One of the key strategies to ending the HIV epidemic in the United States is to increase investments in
geographic hotspots, or areas of elevated disease burden. However, a few key challenges limit the ability for
hotspot mapping to inform effective HIV interventions. First, hotspot mapping typically uses residential address
of an individual with an incident infection. Yet for many individuals, potential risky sex and drug-use behaviors
do not occur at home. Identifying the places in which risk occurs, as opposed to where an individual who
engages in risk lives, will help target and increase exposure to place-based interventions. Second, individual
behavior is often constrained or dictated by larger socio-ecological factors, and these can work together to
create or maintain health disparities. Interventions tailored to risk hotspots to improve the HIV care cascade
need to be responsive to the broader socio-ecological context of the hotspot. Third, an implicit assumption
about prioritizing hotspots for interventions is that efforts to reduce incidence in hotspots will indirectly reduce
incidence elsewhere as well, as infections likely spread from high incidence areas to neighboring lower
prevalence areas. Information on potential geographic and sexual network connectivity between hotspots and
other places can inform prioritization of risk hotspots for HIV interventions.
We will demonstrate innovative methods to identify and prioritize HIV risk hotspots among urban, non-white
men who have sex with men (MSM), populations at especially high-risk for HIV in the United States. We will
leverage and supplement existing longitudinal data on non-White MSM, both HIV-infected and uninfected, from
the ongoing mStudy cohort in Los Angeles, to achieve our goals. We will first adapt an existing web-based
activity space survey of HIV risk and prevention to incorporate geographic characteristics of networks,
residential mobility, and locations of drug use. Then we will use cognitive interviews to validate the survey
instrument, and collect data from 250 MSM using the updated survey. Second, we will identify and describe
HIV transmission and acquisition risk hotspots within Los Angeles County, using individual activity space data
on sexual risk and drug use locations, neighborhood characteristics of the hotspots, and sociodemographic
characteristics and behaviors of individuals engaging in risk in the hotspots. Third, we will estimate
connectivity of hotspots to other locations (e.g., other hotspots, residential locations, and prevention locations),
in order to identify which hotspot to prioritize for maximizing intervention effectiveness over time and space.
This work will improve the effectiveness of HIV prevention, care, and treatment strategies in two ways. First, it
will guide decision making as to which hotspot to prioritize, by ranking them in terms of potential connectivity to
other places, and thus maximizing the reach of the intervention. Second,...

## Key facts

- **NIH application ID:** 10081422
- **Project number:** 1R21DA049643-01A1
- **Recipient organization:** UNIVERSITY OF CALIFORNIA SANTA BARBARA
- **Principal Investigator:** SUSAN LYNN CASSELS
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $220,614
- **Award type:** 1
- **Project period:** 2020-07-01 → 2022-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10081422

## Citation

> US National Institutes of Health, RePORTER application 10081422, Activity spaces for HIV risk and prevention among diverse men who have sex with men in Los Angeles (1R21DA049643-01A1). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10081422. Licensed CC0.

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